Temporal variation of post-accident atmospheric 137 Cs in an evacuated area of Fukushima Prefecture: Size-dependent behaviors of 137 Cs-bearing particles

The seasonal variations of atmospheric 134,137Cs activity and possible host particles for their resuspension in the contaminated areas of Tsushima and Yamakiya, Fukushima, Japan

“…Radiocesium isotopes 134 Cs and 137 Cs were two of the main radionuclides released from the FDNPP accident (Steinhauser et al 2014). As an example, the total amount of released 137 Cs was estimated by Chino et al (2011) to be 1.3 × 10 16 Bq (13 PBq).…”

“…Radiocesium isotopes 134 Cs and 137 Cs were two of the main radionuclides released from the FDNPP accident (Steinhauser et al 2014). As an example, the total amount of released 137 Cs was estimated by Chino et al (2011) to be 1.3 × 10 16 Bq (13 PBq). The 134 Cs emission inventory should be almost the same as that of 137 Cs, i.e., 1.2 × 10 16 Bq (12 PBq; Steinhauser et al 2014) because the activity ratio of these two isotopes was almost united in the case of the FDNPP accident (e.g., Merz et al 2013).…”

“…As an example, the total amount of released 137 Cs was estimated by Chino et al (2011) to be 1.3 × 10 16 Bq (13 PBq). The 134 Cs emission inventory should be almost the same as that of 137 Cs, i.e., 1.2 × 10 16 Bq (12 PBq; Steinhauser et al 2014) because the activity ratio of these two isotopes was almost united in the case of the FDNPP accident (e.g., Merz et al 2013). There have been concerns that the deposited radiocesium will influence the contaminated area for an extended period, in contrast to the effects of radioiodine, because the half-lives of 134 Cs and 137 Cs are relatively long: 2.06 years and 30.17 years, respectively (Dietz and Pachucki 1973;Unterweger 2002).…”

“…The 134 Cs emission inventory should be almost the same as that of 137 Cs, i.e., 1.2 × 10 16 Bq (12 PBq; Steinhauser et al 2014) because the activity ratio of these two isotopes was almost united in the case of the FDNPP accident (e.g., Merz et al 2013). There have been concerns that the deposited radiocesium will influence the contaminated area for an extended period, in contrast to the effects of radioiodine, because the half-lives of 134 Cs and 137 Cs are relatively long: 2.06 years and 30.17 years, respectively (Dietz and Pachucki 1973;Unterweger 2002). Figure 1 shows the contaminated deposition density map for 134,137 Cs (the unit of deposition density is Bq m − 2 ) measured from October to November 2011 by the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) (2011).…”

“…There have been concerns that the deposited radiocesium will influence the contaminated area for an extended period, in contrast to the effects of radioiodine, because the half-lives of 134 Cs and 137 Cs are relatively long: 2.06 years and 30.17 years, respectively (Dietz and Pachucki 1973;Unterweger 2002). Figure 1 shows the contaminated deposition density map for 134,137 Cs (the unit of deposition density is Bq m − 2 ) measured from October to November 2011 by the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) (2011). The radionuclides released by the FDNPP were deposited on the ground, vegetation, houses, and other objects, causing serious contamination of widespread areas, especially areas in the northwest of the FDNPP.…”